The present disclosure relates generally to a method and apparatus for separating objects. More particularly, the invention relates to a method and apparatus for laning, sorting, and rejecting objects.
When objects are conveyed from place to place, for example, in a production or packaging plant, it often is necessary to separate the conveyed objects for various reasons. For instance, it may be necessary to separate the objects into different lanes so that the objects can be acted upon by a relatively slow machine located downstream. Alternatively, it may be desired to sort the objects by any one of several object characteristics, e.g., color, fill level, etc. In other instances, it may be desired to separate defective objects from the acceptable objects. Accordingly, separating devices are called upon to perform the functions of laning, sorting, and/or rejecting objects that are being conveyed.
There have been several prior art devices designed to effect such object separation. One example is disclosed in U.S. Pat. No. 3,433,343, to Giulie. In this reference, Giulie describes a segregating device which uses mechanical, actuatable pistons that are used to physically push the objects being conveyed into one of two possible directions such that the defective objects can be separated from the acceptable ones. To aid in the segregation of these objects, the Giulie segregating device further uses a sheet metal ramp that is oriented at an angle with respect to the infeed conveyor so as to lead the objects in a downward direction away from the infeed conveyor. This ramp includes a central member constructed of a low friction plastic which comprises side walls that form ledges that are designed to guide the article in either of the two directions. Although ostensibly providing for object segregation, the Giulie design presents several disadvantages. First, a high degree of precision is required in operating the segregating device in that it is designed to physically push the object to one side or another with a piston rod. Accordingly, if the timing of actuation of either piston is off, or the length of stroke of the piston rod of either piston is off, device malfunction can occur. In addition, the use of a mechanical actuator such as a piston can require frequent maintenance and/or replacement of mechanical parts over the life of the device. Furthermore, due to the configuration of the ramp, there is a high probability of an object falling over while traveling down the ramp in that no support means beyond the central member are provided. Finally, it is clear from the design of the segregating device that objects of only very particular sizes and shapes can be segregated with the device.
Another device for separating objects is described in U.S. Pat. No. 3,552,537, to Vamvakas. In this patent, Vamvakas discloses a conveyor system comprising an infeed conveyor which feeds two central conveyors arranged in parallel. The first of these central conveyors is a relatively slow moving conveyor while the second is a relatively fast moving conveyor. Positioned in between these two conveyors is a center rail that protrudes above the surface of the two parallel conveyors. As objects are transferred from the infeed conveyor to the central conveyors, some of the objects remain on the slow conveyor while others are forced by other incoming objects beyond the slow conveyor to be swept away by the fast conveyor. The center rail aids in the separation of the objects by causing objects traveling along both the slow and fast conveyors to tilt either toward the slow conveyor or the fast conveyor. Although capable of separating the objects into different lanes, the Vamvakas conveyor system also presents several disadvantages. First, calibration of the conveyor system can be difficult in that the correct speeds must be chosen for the infeed conveyor, the relatively slow conveyor, and the relatively fast conveyor such that generally equal distribution of the objects is obtained. In addition, proper functioning of the conveyor system requires that the objects come into contact with each other. As is known in the art, this object interaction can cause crowding and jams which often require shut-down of the conveyor system and attendant delays. Moreover, the center rail tends to slow down operation of the conveyor system such that, even when the correct speed ratios are selected, high-speed operation of the conveyor system is difficult to maintain. Finally, the conveyor system disclosed by Vamvakas only can be used to lane the objects in that separation of the objects is random and not selective. Accordingly, the Vamvakas conveyor system cannot be used to sort and/or reject objects.
A further device for separating objects is disclosed in U.S. Pat. No. 4,469,218 to Cossxc3xa9. Similar in design to the segregating device disclosed by Giulie, the Cossxc3xa9 separating device comprises an infeed conveyor and a ramp that slopes downwardly therefrom. The ramp is provided with a separating barrier that, similar to the central member of Giulie""s ramp, aids in the separation of the objects. Instead of using an actuatable piston, however, Cossxc3xa9 uses compressed air to force the objects in the desired directions. In particular, Cossxc3xa9 uses a compressed air source that is connected to a delivery pipe that is positioned just upstream of the meeting point of the infeed conveyor and the ramp. The pipe is provided with two outlets that face downwardly toward the objects transported thereunder. To control the sequence in which the compressed air is delivered to the objects, a drum-shaped distributor is disposed about the pipe which has a plurality of elongated apertures positioned in various positions along the periphery of the distributor. During operation, the distributor is rotated about the pipe such that the compressed air leaving the pipe through the outlets only reaches an object when one of the outlets is aligned with a drum aperture. Although the Cossxc3xa9 device can be considered an improvement over the Giulie segregating device in that no mechanical actuators are used to separate the objects, the Cossxc3xa9 separating device cannot be used to selectively separate the objects to obtain either a sorting function or a rejecting function because the blasts of compressed air directed towards the objects are controlled only by the configuration and rotation speed of the distributor. Therefore, the Cossxc3xa9 separating device can only divide the objects into different lanes. In addition, the device must be very carefully synchronized such that the bursts of compressed air reach the conveyor when the objects are positioned under the distributor.
From the foregoing, it can be appreciated that it would be desirable to have a separating device that is capable of selectively laning, sorting, and rejecting objects which is flexible, fast, efficient, and which uses a minimum of moving parts.
The present disclosure relates to a method and apparatus for separating objects. The apparatus typically includes a separation conveyor that forms a shallow peak within a pitched region of the separation conveyor upon which an object travelling along the separation conveyor can be temporarily balanced. The apparatus further includes at least two guide rails extending along the separation conveyor in a laterally spaced relationship. Upstream from the pitched region, the guide rails laterally support objects travelling along the separation conveyor. Within the pitched region, the guide rails are laterally spaced so as to permit lateral displacement of the objects when within the pitched region. At least one nozzle is positioned at a lateral position within the pitched region of the separation conveyor and is oriented so as to be capable of selectively ejecting a burst of gas transversely across the separation conveyor to tip an object balanced on the shallow peak so as to cause the object to be laterally displaced.
In a preferred arrangement, the apparatus further includes at least one sensing device positioned adjacent the at least one nozzle which is electronically connected to a control system which controls activation of the at least one nozzle in response to information sensed by the sensing device. Arranged in this manner, the apparatus can sense either the mere presence of an object or certain predetermined characteristics of the object to determine when the at least one nozzle should be activated to tip the object in a desired direction.
With the herein described apparatus, objects can be selectively directed into separate lanes, sorted into different groups having shared characteristics, or rejected when sensed to be inadequate for any reason.
The features and advantages of the invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawings.